I don’t know.
I think, those are two different issues, @StevenBerlin, but this is just guessing and only Googlers could tell us.
What we called “semi hidden photos” (not reviews!) are those which appear in the Contributions lists when logged in, as well as for anonymous, but never show up at the pin listing under All, Recent or My Photos.
Instead for reviews, according to my observations described above, the list under My Contributions → Reviews is not complete - neither for myself being logged in nor for anonymous.
However, that doesn’t exclude the possibility it could happen for photos too., but for my 7,000 photos, I find them all, if I just scroll long enough. Since you have 10,000 more, it might be different.